Hyperemesis gravidarum, severe vomiting, develops in about 1–2% of all pregnancies. Acupuncture on the point PC6 above the wrist on the palmar side has been found to prevent some types of nausea and vomiting. The purpose of the present study was to see if acupuncture, in addition to standard treatment, could hasten the improvement of hyperemesis gravidarum. Thirty-three women with hyperemesis were evaluated in a randomized, single-blind, crossover comparison of two methods of acupuncture, active (deep) PC6 acupuncture or placebo (superficial) acupuncture. The women estimated their degree of nausea on a visual analogue scale (VAS). The daily number of emesis episodes were documented. Crossover analyses showed that there was a significantly faster reduction of nausea VAS and more women who stopped vomiting after active acupuncture than after placebo acupuncture. This study suggests that active PC6 acupuncture, in combination with standard treatment, could make women with hyperemesis gravidarum better faster than placebo acupuncture.

Acupuncture

The acupuncture treatments were given three times daily on treatment days. Each treatment lasted for 30 minutes. Specially trained midwives who did not interact with the patients concerning the type of acupuncture method used performed the treatments. These midwives did not belong to the ward staff. Two methods of acupuncture were used: (1) active, deep (“de-qi”) acupuncture, in which a needle was inserted approximately 5 cm above the wrist crease on both forearms. The traditional acupuncture point PC6 is located between the tendons of the palmaris longus and flexor carpi radialis muscles at a depth just above the median nerve. A tingling sensation (“deqi”) radiating to the hand and/or fingers was searched for when inserting the needles and again each 10 minutes of treatment; and (2) placebo (superficial) acupuncture, in which a needle was inserted 10 cm from the wrist on the thumb side of both forearms. The needle was just inserted 1–2 mm in the skin, intracutaneously or superficially subcutaneously. No “de-qi” sensation was searched but the needles were twisted a little every 10 minutes of treatment.

Results

Nausea

The VAS estimates for nausea experienced on day 0 was different between Groups A and B, (P = 0.009, Mann-Whitney). Due to this finding, it was not possible to directly compare the VAS values between the groups. Instead, we have analyzed the speed of VAS-reductions in our crossover analyses (Figure 3). The VAS-reductions were calculated as the difference between the VAS estimates the day before acupuncture and those the day following the two acupuncture days for each patient. This intergroup crossover analysis showed a significantly faster reduction of nausea when giving the patients active acupuncture than when giving them placebo acupuncture (P = 0.032, Mann-Whitney). There was no period effect (P = 0.138).

It was also found that the VAS-reductions between day 0 and day 1 and between day 4 and day 5 were significantly faster when the patients received the active treatments (P = 0.009, Mann-Whitney). This, too, was not a period effect, (P = 0.828). Intragroup analyses showed that the changes in absolute VAS-values from day 0 to day 1 and day 4 to day 5 were significant only in the active acupuncture group (P = 0.007 and 0.019, Wilcoxon) and not in the placebo acupuncture group (P = 0.475 and 0.570).

Vomiting

All women were vomiting on day 0. The number of women vomiting on the third day (the day following the two acupuncture days) was reduced to 7/17 in Group A (active treatment) and 12/16 in Group B (placebo treatment). This difference is significant between the two groups (P = 0.049, χ²-test). After day 4 a further significant decrease in the number of women vomiting was observed in Group B, which included patients who received active treatments day 5 and day 6 (P = 0.031, McNemars test).

Food Intake

The increase in food intake from day 0 to day 2 was significant in Group A (P = 0.030) but not in Group B (P = 0.564, McNemars test). No significant difference was seen between the groups.

Intravenous Fluids

The amount of intravenous fluid fell in both groups very fast from admission to discharge. There were significant reductions in both groups from day 0 to all other days, but no overall group difference could be seen.

Side Effects

No side effect of any kind was seen during or after the study.

An interesting possibility to explain the acupuncture effects on nausea/vomiting is that gastric emptying may be influenced by acupuncture by means of such somatovisceral reflexes. Sato et al.’s research group has shown that noxious and acupuncture-like stimulation can induce both inhibitory and facilitating responses on the motility in the stomach and small intestine of anesthetized rats.30 When stimulation was performed to the abdominal skin, an inhibitory effect was found. When stimulation was done on the lower or upper limbs (in the area approximately at PC6), an immediate motility facilitating effect, transmitted by vagal efferents, was found. These effects were not influenced by naloxone, and are thus probably not mediated through the endorphin system.

In our study, we observed that the effect of acupuncture on vomiting was very fast, often within minutes of stimulation, indicating a neural substrate. The somatovisceral reflexes might give us an understanding of the acupuncture effects on different kinds of nausea and vomiting, as their effect duration is consistent with what we clinically observe.

Conclusion

The present study, however limited, strongly indicates that acupuncture has a clinically useful effect in hyperemesis gravidarum. The clinical impact of the technique, however, has to be evaluated in further studies.